A pilot study suggests that a novel treatment for blood clots in the legs is safe and effective.
Published in the journal Radiology, the study showed that deep vein thrombosis (DVT) could be effectively treated by injecting or "lacing" the clot with a fibre-binding thrombolytic agent. The therapy was also found to reduce the risk of subsequent recurrence or bleeding.
"This treatment regimen is able to clear blood clots rapidly and safely, restoring blood flow in the veins of the lower leg, and the results are durable," said lead author Dr. Richard Chang, chief of the interventional radiology section of the Department of Radiology, Clinical Center, National Institutes of Health (NIH), Bethesda.
DVT is a common and serious health problem in which a blood clot, or thrombus, form in the deep veins, particularly in the lower leg or thigh. Complications occur when the clot breaks off and travels to the lungs, resulting in a potentially fatal condition called pulmonary embolism.
Most patients with the condition are treated solely with anticoagulation therapy (blood thinners) and compression stockings. However, one-third of such patients suffer from post-thrombotic syndrome—characterised by pain, swelling, or in severe cases by changes in skin colour or skin ulceration—while another third are likely to have another clot or pulmonary embolism within five years of their initial DVT.
Though thrombolytic (clot-dissolving) therapy can potentially prevent such occurrences, it poses a bleeding risk.
With a view to developing a safe, effective and affordable thrombolytic treatment regimen, Dr. Chang and his colleagues treated 20 acute DVT patients with direct intraclot lacing of the thrombus with a clot-dissolving agent called alteplase and full systemic anticoagulation.
Since alteplase binds to the clot, the procedure does not require continuous infusion of the drug, as do some thrombolytic therapies.
After lacing one vein segment, the interventional radiologist can immediately direct catheters to treat other vein segments to ensure that the entire clot has been adequately treated.
The researchers observed that blood flow was restored throughout the deep venous system in 16 of the 20 patients during therapy, with complete resolution of symptoms in 18 patients after six months of anticoagulation.
The risk of subsequent bleeding was reduced by clearing alteplase from the patients' circulatory system within two hours of treatment.
According to the researchers, there were no serious complications or bleeding during the treatment, and no cases of post-thrombotic syndrome or recurrent clotting during follow-up of 3.4 years.
"With this therapy, pain and swelling resolve rapidly, and, in most cases, the patient is able to resume all normal activity within a week," said the study's co-author, Dr. McDonald K. Horne III from the hematology section of the Department of Lab Medicine, Clinical Center, NIH.
The authors of the study, however, admit that more research is required to further support the efficacy of this promising treatment.